Gas turbine engines are known to include a compressor section for supplying a flow of compressed combustion air, a combustor section for burning fuel in the compressed combustion air, and a turbine section for extracting thermal energy from the combustion air and converting that energy into mechanical energy in the form of a rotating shaft. Many components that form the combustor and turbine sections are directly exposed to hot combustion gases, for example, the combustor liner, the transition duct between the combustor and turbine sections, and the turbine stationary vanes and rotating blades and surrounding ring segments.
It is also known that increasing the firing temperature of the combustion gas can increase the power and efficiency of the combustion turbine. Modern high efficiency combustion turbines have firing temperatures that exceed temperatures of about 1,600° C., and even higher firing temperatures are expected as the demand for more efficient engines continues. Thus, the cobalt and nickel based superalloy materials traditionally used to fabricate the structural gas turbine components must be aggressively cooled and/or insulated from the hot gas flow in order to survive long term operation in the aggressive high temperature combustion environment. Additionally, certain combustion turbine components and configurations demand that the insulating material also provide structural mechanical support and strength. For example, it is known to use ceramic tiles to form the combustion liner within the combustion section of the engine.
An issue associated with these structural ceramic tiles, however, is that they are known to crack when operational local stresses exceed the ceramic material properties. To further complicate matters, these cracks are caused by a variety of factors and formed in a variety of locations. If left unresolved, these cracks can propagate and expand until the tile fails. Thus, expense and time consuming periodic inspections are frequently required to ensure the tile are not cracked.
Accordingly, there is a need to reduce the time and cost associated with cracked ceramic combustion liner tiles. There is also a need to reduce the formation of cracks on ceramic combustion liner tiles.